Arizona immigration law: states vs. Obama at US Supreme Court, again‎

"On April 25, the issue before the justices is whether Arizona exceeded its authority when it passed a tough immigration enforcement statute, Senate Bill 1070, designed to encourage illegal immigrants to pack up and leave.

The Arizona strategy is called 'attrition through enforcement.' The Arizona case comes roughly a month after 26 states argued at the high court that Congress had overstepped its authority in passing the president's health-care reform law."